This invention relates in general to electrical socket terminals and, in particular, to an assembly of a contact spring and wire wrap terminal.
More specifically, without limitation to the particular use which is shown and described, this invention relates to a contact spring clip and wire wrap terminal, comprising a two-piece construction which is fabricated from separately stamped and formed flat stock. The material of the spring may differ from the wire wrap terminal for increased economy and enhanced service characteristics. Expensive metal plating to increase contact may be selectively applied to the contact elements for added economy in manufacture.
Socket terminals are commonly employed to interconnect electrical devices with a circuit. The pins of the component may be plugged directly into the terminal for an effective connection. The terminal can be directly mounted on a circuit board or by use of a socket assembly and has a terminal end for interconnections with the electrical circuit by soldering and/or wire wrap techniques. In the prior designs, one type of socket terminal is a one piece device constructed from a single material. A one piece component suffers from several deficiencies, including the fact that the necessity of using only one material in its construction makes it more expensive to manufacture, because of the high cost of heavily plating the entire terminal.
In use, it is advantageous that the inner contact be formed from a flexible, high conductive material, such as copper and the like, while the socket terminal may be brass or any other material. Such flexibility is severely limited in a one piece design of the contact and terminal, since a single material is required. Typical techniques of manufacturing one piece sockets for circuit boards also generally result in a high profile of the contact, meaning the pin or contact projects too far up from the voltage plane side of the traditional printed circuit board. In use, such a high profile is disadvantageous from design considerations.
To solve the problems presented by one piece sockets, certain terminals have been introduced employing a two-piece design where the contact and the terminal are constructed from different materials offering better performance characteristics and less fabrication expense, depending on the function of the element within the assembly. Known two-piece socket designs, however, have disadvantageously been heretofore machined in manufacture. The necessity to precision machine such two-piece assemblies decreases the overall economy of fabrication of the terminal. The cost of manufacture of prior two-piece designs is also increased by requirement that gold plating, or the application of other conductive materials, must be made to the entire surface of the contact area, because selective plating of machined components is extremely difficult. Known two-piece designs of the machined type are further deficient in providing accurate orientation of the terminal when mounted on the board. It is advantageous that the contact spring tines be aligned with the flats on the socket terminal which, in turn, assures the four tines of the spring contact mates with both the sides and edges of the leads of the plug-in active device when the assembly is properly inserted into a socket or printed circuit board.